Communication modules, such as electronic or optoelectronic transceivers or transponder modules, are increasingly used in electronic and optoelectronic communication. Each communication module typically communicates with a host device printed circuit board by transmitting and/or receiving electrical data signals to and/or from the host device printed circuit board. The communication module can also transmit electrical data signals outside a host device as optical and/or electrical data signals. Many communication modules include optical subassemblies (individually, an “OSA”) such as transmitter optical subassemblies (individually, a “TOSA”) and/or receiver optical subassemblies (individually, a “ROSA”) to convert between the electrical and optical domains.
Generally, a ROSA transforms an optical signal received from an optical fiber or other source to an electrical signal provided to the host device, while a TOSA transforms an electrical signal received from the host device to an optical signal emitted onto an optical fiber or other transmission medium. A photodiode or similar optical receiver contained by the ROSA transforms the optical signal to the electrical signal. A laser diode or similar optical transmitter contained within the optical subassembly is driven to emit an optical signal representing the electrical signal received from the host device.